The goal of this program continues to be the development of instrumentation and techniques for measurement of cardiovascular variables in intact animals and man to enable test of hypotheses regarding cardiovascular function and control mechanisms. Three instruments will be developed. A gas flow meter for measurement of ventilation gas flow rates in animals and humans will be developed utilizing a new frequency modulated ultrasonic carrier technique. A new technique for continuous measurement of small regional segments of myocardium will be developed utilizing the transit time of sound among small, closely spaced crystals embedded within the myocardium. A new technique for measurement of efferent and afferent neural traffic along cardiovascular nerve trunks in chronic animal preparations will be developed. Each of these instruments will be employed in experiments designed to provide a description of normal and abnormal cardiovascular dynamics in intact animals.